Crystalline forms of tyrosine kinase inhibitors and their salts

ABSTRACT

The invention relates to various polymorphic forms and amorphous form of sodium 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzate, including the polymorphic form A, mixtures of the polymorphs, process for the preparation thereof and the use thereof in a pharmaceutical composition containing thereof.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a Continuation application of U.S. application Ser. No. 14/208,244, filed on Mar. 13, 2014, which claims the benefit of priority to U.S. Provisional Application No. 61/801,112, filed Mar. 15, 2013, the entire contents of each of which are hereby incorporated by reference in their entirety for all purposes.

FIELD OF THE INVENTION

The invention relates to a novel composition and polymorphs of sodium 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzate, particularly the polymorphic form A, mixtures of the polymorphs, process for the preparation thereof and the use thereof in a pharmaceutical composition containing thereof.

BACKGROUND

The free acid of compound 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoic acid (“Compound 701”) and its pharmaceutical composition are known in US Patent Application No. 20110301133 A1 (corresponding PCT Patent Application, WO2009/067197, which is hereby incorporated by reference) and has the following chemical structure:

Compound 701, and the physiologically acceptable salts thereof, have valuable pharmacological properties. Compound 701 is a receptor tyrosine kinase inhibitor, particularly a potent NGF receptor TrkA inhibitor which, by virtue of its pharmacological properties, may be used, for examples, for the treatment and/or prevention of acute and chronic pain, cancer, restenosis, atherosclerosis, psoriasis, thrombosis, skin diseases, inflammation, inflammation related diseases, or a disease, disorder or injury relating to dysmyelination or demyelination. Other possible therapeutic applications can be found in WO2009/067197, the contents of which are hereby referred to.

Due to the limited solubility of the free acid Compound 701, it is very difficult to achieve practical oral bioavailability in the in-vivo systems, for example, in rat. Salt formation has been widely used in the art to improve lipophilic, water solubility and/or oral bioavailability, among other issues in the industry. However, it is problematic and huge challenge for selection and testing of the enormous numbers of possible salt forms in practice, since Compound 701 is zwitterionic molecule, there are vast amount of counterions and/or molecules that could form salts or co-crystals with Compound 701 and they can be from either (i) anionic counter-ions, for examples, acetate, benzoate, bicarbonate, bisulfite, norate, bromide, carbonate, chloride, citrate, formate, fumerate, glcuconate, glucuronate, hydrochloride, malate, nitrate, phosphate, salicylate, succinate and tartrate; (ii) cationic counter-ions, for examples, ammonium, piperazine, diethlyamine, diethanolamine, imidazole, diethylammonium, ethylenediamine, betaine, lithium, sodium, potassium, calcium, magnesium, aluminum, zinc, bismuth and stonium; or (iii) zwitterionic molecules, for examples, glycine, bicine, tricine, sulfamic acid, lysergic acid, and psilocybin. Furthermore, each salt or co-crystal forms may form various polymorphs with various degrees of physicochemical properties in terms of, for examples, solubility, stability, and oral bioavailability, it is therefore problematic and huge challenge in practice.

Another aspect which is important in drug development is that the active substance should have the most stable possible crystalline morphology for the pharmaceutical quality of a medicinal formulation. If this is not the case, the morphology of the active substance may change in certain circumstances under the conditions of manufacture of the preparation. Such a change may in turn affect the reproducibility of the manufacturing process and thus lead to final formulations which do not meet the high quality requirements imposed on pharmaceutical formulations. To this extent it should generally be borne in mind that any change to the solid state of a pharmaceutical composition which can improve its physical and chemical stability gives a significant advantage over less stable forms of the same drug.

SUMMARY OF THE INVENTION

The present invention provides, among other things, small molecule compounds and their salts or solvates in various crystalline forms and amorphous form as NGF receptor TrkA inhibitor and/or antagonist for the preparation of a medicament for the treatment and/or prevention of diseases associated, directly or indirectly with modulation of activity or expression of TrkA protein kinase, which include pain, cancer, restenosis, atherosclerosis, psoriasis, skin diseases, thrombosis, or a disease, disorder or injury relating to dysmyelination or demyelination.

In one aspect, the present invention provide a compound of the following structure in various crystalline forms and amorphous form:

Sodium 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoate

In one embodiment, a crystalline polymorph of Compound I is crystalline polymorph Form A. In another embodiment, the crystalline polymorph exhibits an x-ray powder diffraction pattern having peak positions at degree two-theta of 10.0±0.3, 20.1±0.3, and 23.6±0.3. In another embodiment, the crystalline polymorph exhibits an x-ray powder diffraction pattern having peak positions at degree two-theta of one or more of 14.5±0.3 and 18.1±0.3, and 9.7±0.3 and 21.2±0.3. In a further embodiment, the crystalline polymorph exhibits an x-ray powder diffraction pattern having at least three, at least five, at least seven, at least ten, or all, of the following peak positions at degree two-theta: 7.160, 8.757, 9.820, 10.161, 12.459, 14.641, 15.219, 17.680, 18.240, 19.104, 20.220, 21.381, 22.579, 23.721, 24.898, 25.761, 25.522, 27.161, 28.321, 28.321, 29.481, 30.921, and 34.281.

In a further embodiment, a crystalline polymorph of Compound I of claim 1 is crystalline polymorph Form B. In a still further embodiment, the crystalline polymorph exhibits an x-ray powder diffraction pattern having three or more, or five or more, or seven or more, or all of, the peak positions at degree two-theta selected from the group consisting of 9.8±0.3, 10.2±0.3, 14.5±0.3, 17.8±0.3, 18.5±0.3, 19.6±0.3, 21.0±0.3, 21.7±0.3, and 23.1±0.3. In yet another embodiment, the crystalline polymorph exhibits an x-ray powder diffraction pattern having three or more, or five or more, or seven or more, or ten or more, or all of, the peak positions at degree two-theta selected from the group consisting of 9.8±0.3, 10.2±0.3, 14.5±0.3, 17.8±0.3, 18.5±0.3, 19.6±0.3, 21.0±0.3, 21.7±0.3, 23.1±0.3, 25.0±0.3, 25.6±0.3, 28.4±0.3, 29.4±0.3, 30.2±0.3, and 31.6±0.3.

In an additional embodiment, a crystalline polymorph of Compound I of claim 1 is crystalline polymorph Form C. In another embodiment, the crystalline polymorph exhibits an x-ray powder diffraction pattern having at least three, at least five, at least seven, or all, of the following peak positions at degree two-theta: 9.8±0.3, 10.2±0.3, 14.3±0.3, 17.4±0.3, 18.2±0.3, 18.9±0.3, 19.2±0.3, 22.1±0.3, 22.7±0.3, and 29.1±0.3. In still another embodiment, the crystalline polymorph exhibits an x-ray powder diffraction pattern having at least three, at least five, at least seven, at least ten, or all, of the following peak positions at degree two-theta: 9.0±0.3, 9.8±0.3, 10.2±0.3, 14.3±0.3, 15.9±0.3, 17.4±0.3, 18.2±0.3, 18.9±0.3, 19.2±0.3, 19.6±0.3, 20.2±0.3, 21.3±0.3, 22.1±0.3, 22.7±0.3, 24.7±0.3, 28.3±0.3, 28.9±0.3, 29.1±0.3, and 30.1±0.3.

In some embodiments, the crystalline polymorph of Compound I is polymorph Form D. In some other embodiments, the crystalline polymorph exhibits an x-ray powder diffraction pattern having peak positions at degree two-theta of 5.6±0.3, 26.0±0.3, and 26.7±0.3. In some additional embodiments, the crystalline polymorph exhibits an x-ray powder diffraction pattern having peak positions at degree two-theta of 8.5±0.3 and 19.3±0.3. In some further embodiments, the crystalline polymorph exhibits an x-ray powder diffraction pattern having at least three, at least five, at least seven, at least ten, or all, of the following peak positions at degree two-theta: 5.58, 7.43, 8.45, 9.21, 11.23, 11.98, 14.86, 17.025, 18.91, 22.80, 26.03, and 26.72.

In particular embodiments, the crystalline polymorph of Compound I is polymorph Form E. In other embodiments, the crystalline polymorph exhibits an x-ray powder diffraction pattern the peak positions at degree two-theta of 5.6±0.3, 14.4±0.3, and 23.5±0.3. In further embodiments, the crystalline polymorph exhibits an x-ray powder diffraction pattern the peak positions at degree two-theta of 18.9±0.3 and 21.0±0.3. In yet further embodiments, the crystalline polymorph exhibits an x-ray powder diffraction pattern having three or more, five or more, seven or more, ten or more, or all of, the peak positions at degree two-theta selected from the group consisting of 5.570, 6.846, 8.552, 9.505, 11.786, 14.374, 17.060, 17.431, 18.006, 18.893, 19.971, 21.015, 22.347, 22.840, 23.528, 25.496, 26.393, 28.264, 29.563, 30.710, 32.263, and 34.045.

In still further embodiments, Compound I is in an amorphous form.

Additional embodiments include a combination of any of the foregoing embodiments and one or more pharmaceutically acceptable excipients. Other embodiments include a dosage form, such as a solid or semi-solid dosage form, comprising any of the foregoing crystal forms, amorphous forms, or combinations. In yet other embodiments, a dosage form comprising any of the foregoing crystal forms, amorphous forms, or combinations comprises one or more of a tablet, hard capsule, soft capsule, powder, suppository, and gel, or one or more of an injectable form, a transdermal patch, a sprayable form, and an implantable depot.

Other embodiments are a use of any of the foregoing embodiments in making a dosage form for inhibiting, or for inhibiting, a NGF receptor. Still other embodiments are a use of any of the foregoing embodiments in making a dosage form for treating a disorder, disease or condition selected from the group consisting of acute and chronic pain, cancer, restenosis, atherosclerosis, psoriasis, thrombosis, skin diseases, inflammation, inflammation related diseases, or a disease, disorder or injury relating to dysmyelination or demyelination.

Surprisingly, the Compound I's oral bioavailability is dramatically increased to about 90 to 100% in rat, which represents a significant improvement compared to about less than 20% oral bioavailability in rat of the free acid Compound 701.

In another aspect, the invention provides pharmaceutical compositions comprising the compound described above, and a pharmaceutically acceptable vehicle.

In another aspect, the invention provides a method of use of Compound I in medical treatment and prevention.

In another aspect, the invention provides a method for preparing Compound I described above.

In another aspect, the invention provides most stable polymorphic forms of Compound I and preparation processes.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing time-dependent pain relieving effect of Compound I (s.c.) in CFA-induced rat inflammatory pain.

FIG. 2 is a graph showing oral dose-dependent reduction of neuropathic pain of the test article in rat model of neuropathic (CCI) pain.

FIG. 3 is 1H-NMR spectra of the polymorph Form A of Compound I.

FIG. 4 is X-ray powder diffraction (XRPD) spectra of the polymorph Form A of Compound I.

FIG. 5 is Raman spectra of the polymorph Form A of Compound I.

FIG. 6 is Differential Scanning Calorimetry (DSC) spectra of polymorph Form A of Compound I.

FIG. 7 is XRPD overlay polymorph Form A of Compound I at 40° C./75% RH T=0 (top) vs T=7 days.

FIG. 8 is XRPD overlay polymorph Form A of Compound I at 80° C. T=0 (top) vs T=7 days.

FIG. 9 is STA spectra polymorph Form A of Compound I.

FIG. 10 is Raman spectra overlay of the polymorph Form A of Compound I at T=0 (bottom) vs T=7 days (middle, 40° C./75% RH) and T=7 days (top, 80° C.).

FIG. 11 is X-ray powder diffraction (XRPD) spectra of the polymorphic form, Form B of Compound I.

FIG. 12 is STA spectra of the polymorphic form, Form B of Compound I.

FIG. 13 is DSC spectra of the polymorphic form, Form B of Compound I.

FIG. 14 is X-ray powder diffraction (XRPD) spectra of the polymorphic form, Form C of Compound I.

FIG. 15 is X-ray powder diffraction (XRPD) spectra of the amorphous Compound I.

FIG. 16 is X-ray powder diffraction (XRPD) spectra of the polymorphic form, Form D of Compound I.

FIG. 17 is X-ray powder diffraction (XRPD) spectra of the polymorphic form, Form E of Formula I compound.

DETAILED DESCRIPTION OF THE INVENTION

It should be understood that singular prepositions such as “a,” “an,” and “the,” are often used for convenience, however, all instances of the singular are intended to encompass the plural unless otherwise indicated either explicitly or from context. Further, it should be understood that all references, including journal articles, books, patents, technical documents, and the like, mentioned in this disclosure are hereby incorporated by reference in their entirety and for all purposes.

In one aspect of the present invention, a compound has the following structure:

Sodium 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoate

The present invention includes amorphous form of Compound I as well as various polymorphic forms of Compound I. Polymorphism can be characterized as the ability of a compound to crystallize into different crystal forms, while maintaining the same chemical formula. A crystalline polymorph of a given drug substance is chemically identical to any other crystalline polymorph of that drug substance in containing the same atoms bonded to one another in the same way, but differs in its crystal forms, which can affect one or more physical properties, such as stability, solubility, melting point, bulk density, flow properties, bioavailability, etc.

In one embodiment, the crystalline forms are characterized by the interlattice plane intervals determined by a X-ray powder diffraction pattern. The spectrum of XRD is typically represented by a diagram plotting the intensity of the peaks versus the location of the peaks, i.e., diffraction angle 2θ (two-theta) in degrees. The intensities are often given in parenthesis with the following abbreviations: very strong=vst; strong=st; medium=m; weak=w; and very weak=vw. In one embodiment, the intensity of about 81% to 100% is very strong; the intensity of about 61% to 80% is strong; the intensity of about 41% to 60% is medium; the intensity of about 21% to 40% is weak; and the intensity of about 1% to 20% is very weak. The characteristic peaks of a given XRD can be selected according to the peak locations and their relative intensity to conveniently distinguish this crystalline structure from others.

Those skilled in the art recognize that the measurements of the XRD peak locations and/or intensity for a given crystalline form of the same compound will vary within a margin of error. The values of degree 2θ allow appropriate error margins. Typically, the error margins are represented by “±”. For example, the degree 2θ of about “9.7±0.3” denotes a range from about 9.7+0.3, i.e., about 10.0, to about 9.7−0.3, i.e., about 9.4. Depending on the sample preparation techniques, the calibration techniques applied to the instruments, human operational variation, and etc, those skilled in the art recognize that the appropriate error of margins for a XRD can be ±0.5; ±0.4; ±0.3; ±0.2; ±0.1; ±0.05; or less.

The term “substantially similar” as used herein means an analytical spectrum, such as XRD pattern, ¹H-NMR spectrum, FT-IR spectrum, Raman spectrum, TGA thermogram, etc., which resembles the reference spectrum to a great degree in both the peak locations and their intensity.

In one specific embodiment, a process for the preparation of Compound I, comprising the following steps:

Preparation of Intermediate 5.

Mixing 4-amino benzoic acid and lithium hydroxide in DMAc, then adding 3,5-dibromo-6H-anthra[1,9-cd]isoxazol-6-one into the mixture and raising the temperature to about 45° C. to 55° C. Stirring the reaction mixture for 18-20 hours. Slowly adding MTBE to the reaction mixture and then cooling to 0 to 10° C. Filtering the solid and drying at room temperature to get 4-((3-bromo-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoic acid (Intermediate 5).

Preparation of Intermediate 6.

Dissolving 4-((3-bromo-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoic acid in DMSO, then adding triethylamine and 1-cyclohexyl piperazine (2a) into the solution. Raising temperature to 60-70° C. After 2-3 hours, slowly adding MTBE and MeOH solution and cooling to room temperature. Isolation and washing of the wet cake with MTBE and MeOH followed by filtering provided 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoic acid (Intermediate 6) as a solid.

Preparation of Compound I.

Dissolving intermediate 6, 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoic acid in sodium hydroxide in methanol solution. Raising temperature to about 40° C. and maintaining for 2-3 hours. Then lowering temperature and filtering solid to get Compound I, sodium 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoate. The compound was purified in sodium hydroxide in methanol solution and dried. It gave more than 99% (HPLC, area %) purity and about 45% yield. Mass spectra gave [M+1]=523.2. ¹H-NMR (400 MHz, DMSO-d6, see also FIG. 3), ppm (δ): 11.79 (1H, s), 8.48 (1H, d), 8.20 (1H, d), 7.93 (2H, d), 7.84 (1H, t), 7.72 (1H, t), 7.35 (2H, d), 6.39 (1H, s), 3.85 (4H, m), 2.72-2.70 (4H, m), 2.28-2.265 (1H, m), 1.72-1.78 (4H, m), 1.55-1.58 (1H, m), 1.08-1.23 (5H, m).

In another aspect of the present invention, crystalline polymorphs of Compound I are studied and synthesized.

In one of crystalline polymorphs, Form A of Compound I, wherein it is characterized by X-ray Powder Diffraction (XRPD) having one or more characteristic peak positions of 9.7±0.3, 10.0±0.3, 14.5±0.3, 17.5±0.3, 18.1±0.3, 20.1±0.3, 21.2±0.3, and 23.6±0.3 degree 2-theta.

The crystalline polymorph Form A of Compound I is further characterized by XRPD having one or more peak positions of 7.0±0.3, 8.6±0.3, 9.7±0.3, 10.0±0.3, 12.3±0.3, 14.5±0.3, 15.1±0.3, 17.5±0.3, 18.1±0.3, 19.0±0.3, 20.1±0.3, 21.2±0.3, 22.4±0.3, 23.6±0.3, 24.6±0.3, 25.6±0.3, 26.5±0.3, 28.2±0.3, 29.4±0.3, 30.6±0.3, 34.1±0.3 and 35.0±0.3 degree 2-theta.

In another aspect, the present invention comprises another crystalline form (Form B) of the Compound I described above, XRPD peaks at one or more of 9.8±0.3, 10.2±0.3, 14.5±0.3, 17.8±0.3, 18.5±0.3, 19.6±0.3, 21.0±0.3, 21.7±0.3, 23.1±0.3, degree 2-theta.

In another aspect, the present invention comprises another crystalline form (Form B) of the Compound I described above, XRPD peaks at one or more of 9.8±0.3, 10.2±0.3, 14.5±0.3, 17.8±0.3, 18.5±0.3, 19.6±0.3, 21.0±0.3, 21.7±0.3, 23.1±0.3, 25.0±0.3, 25.6±0.3, 28.4±0.3, 29.4±0.3, 30.2±0.3, 31.6±0.3 degree 2-theta. An example of Form B is given in FIG. 11. Form B can be a hydrate or hemi-hydrate polymorphic form, however, experimental results are consistant with the proposition that Form B does not convert to Form A upon simple heating or drying.

In another aspect, the present invention comprises a third crystalline form (Form C) of the Compound I described above, XRPD peaks at one or more of 9.8±0.3, 10.2±0.3, 14.3±0.3, 17.4±0.3, 18.2±0.3, 18.9±0.3, 19.2±0.3, 22.1±0.3, 22.7±0.3, 29.1±0.3, degree 2-theta.

In another aspect, the present invention comprises a third crystalline form (Form C) of the Compound I described above, XRPD peaks at one or more of 9.0±0.3, 9.8±0.3, 10.2±0.3, 14.3±0.3, 15.9±0.3, 17.4±0.3, 18.2±0.3, 18.9±0.3, 19.2±0.3, 19.6±0.3, 20.2±0.3, 21.3±0.3, 22.1±0.3, 22.7±0.3, 24.7±0.3, 28.3±0.3, 28.9±0.3, 29.1±0.3, 30.1±0.3 degree 2-theta. An example of Form C is given in FIG. 14.

In another aspect, the present invention comprises a third crystalline form (Form D) of the Compound I described above, XRPD peaks at one or more of 5.6±0.3, 8.5±0.3, 14.9±0.3, 17.0±0.3, 26.0±0.3, 26.7±0.3, degree 2-theta.

In another aspect, the present invention comprises a third crystalline form (Form D) of the Compound I described above, XRPD peaks at one or more of 5.6±0.3, 7.4±0.3, 8.5±0.3, 9.2±0.3, 11.2±0.3, 12.0±0.3, 14.9±0.3, 17.0±0.3, 18.9±0.3, 22.8±0.3, 26.0±0.3, 26.7±0.3, degree 2-theta. An example of Form D is given in FIG. 16.

An amorphous form of Compound I was also found and characterized by XRPD. An example of amorphous of Compound I is given in FIG. 15.

In another aspect, the present invention comprises a method of producing the crystalline form of Compound I described above.

Example 1 Preparation of 4-((3-bromo-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoic acid

About 70 g of 4-amino benzoic acid and 22 g of lithium hydroxide were mixed in 800 mL of DMAc. Then 100 g of 3,5-dibromo-6H-anthra[1,9-cd]isoxazol-6-one was dissolved in the pre-mixed solution. Nitrogen protection was applied to the reaction mixture at 45-55° C. for about 18-20 hours. After reaction completion was confirmed by HPLC, 30 mL of MTBE was slowly added to the reactor. Reaction mixture was then slowly cooled to 0-10° C. under nitrogen protection. Centrifuged the solid and washed with 18 mL of MTBE. Dried the wet cake under 25-30° C. to obtain about 69 g of 4-((3-bromo-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoic acid.

Example 2 Preparation of 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoic acid

About 70 g of 4-((3-bromo-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoic acid was dissolved in 950 mL of DMSO. About 50 mL of TEA and 50 g of 1-cyclohexyl piperazine were added to the reaction. Temperature was raised to 60-70° C. After 2-3 hours, slowly added 500 mL of MTBE and MeOH (10:1) solution and adjusted the temperature to 40-50° C. The solid was centrifuged and washed by 100 mL of MTBE and MeOH solution and followed by 100 mL of MeOH. Solid was dried under reduced pressure at 25-30° C. for 12-24 hours to obtain the 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoic acid at about 98% purity and about 91% yield.

Example 3 Preparation of sodium 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoate

About 80 g of 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoic acid was slurred in 2500 mL of 0.4 M NaOH/MeOH between 40-45° C. for 2-4 hours. After confirmed the reaction completion by HPLC, slowly cooled the reaction to room temperature. The solid was centrifuged and washed with 20 mL of MTBE. The wet cake was re-suspended in about 1000 mL of 0.1M NaOH in MeOH solution under room temperature. It was centrifuged and washed with 224 mL of MTBE again. The filtered solid was suspended in 996 mL of MTBE under room temperature for 1-2 hours. The solid was separated and dried at 25-30° C. under pressure for 12-24 hours to obtain the final desired product with purity more than 99% and about 90% yield. Mass spectra give [M+1]=523.2. ¹H-NMR (400 MHz, DMSO-d6, see FIG. 3), ppm (δ): 11.79 (1H, s), 8.48 (1H, d), 8.20 (1H, d), 7.93 (2H, d), 7.84 (1H, t), 7.72 (1H, t), 7.35 (2H, d), 6.39 (1H, s), 3.85 (4H, m), 2.72-2.70 (4H, m), 2.28-2.265 (1H, m), 1.72-1.78 (4H, m), 1.55-1.58 (1H, m), 1.08-1.23 (5H, m). Sodium content is 3.8%. The Raman spectrum is shown in FIG. 5. The XRPD, see Table below and FIG. 4, confirmed the polymorphic form.

TABLE 1 XRPD Table of the polymorphic form, Form A of Compound I. Angle d-value Intensity # 2-Theta° (Angstrom) (%) 1 7.160 12.3354 14.3 2 8.757 10.0899 22.4 3 9.820 9.0001 70.1 4 10.161 8.6986 88.1 5 10.522 8.4006 7.3 6 12.459 7.0985 14.5 7 14.641 6.0454 82.0 8 15.219 5.8170 22.8 9 17.680 5.0124 41.0 10 18.240 4.8598 73.0 11 19.104 4.6420 14.2 12 20.220 4.3883 100.0 13 21.381 4.1525 33.3 14 22.579 3.9347 10.1 15 23.721 3.7478 99.7 16 24.898 3.6733 11.8 17 25.761 3.4555 17.8 18 25.522 3.3581 13.6 19 27.161 3.2804 17.7 20 28.321 3.1487 10.5 21 29.481 3.0273 12.8 22 29.781 2.9976 8.7 23 30.478 2.9306 7.7 24 30.921 2.8896 18.6 25 34.281 2.6137 12.1 26 35.120 2.5532 8.0 27 35.483 2.5279 6.0

Accelerated stability tests of Compound I at 40° C./75% RH and 80° C. detected no instability as measured by XRPD and Raman over 1 week, see FIG. 7 and FIG. 8 and FIG. 10. Thus, Form A is a stable polymorphic form which is particularly useful for pharmaceutical compositions.

STA data (FIG. 9) indicated the Compound I was not hydrated or solvated. The DSC data did not indicate a clear melt up to about 200° C., as shown in FIG. 6.

Form B was prepared by using slurry method from either amorphous Compound I or other polymorphic forms with solvent of ethanol:water (9:1), which was followed by drying under reduced pressure and ambient temperature.

Form C was prepared by using slurry method from either amorphous Compound I or other polymorphic forms with solvent of THF:water (7:3), which was followed by drying under reduced pressure and ambient temperature.

Form D was prepared by using methanol recrystallization process from either amorphous Compound I or other polymorphic forms, which was followed by drying under reduced pressure and ambient temperature.

Form E was prepared from either amorphous Compound I or other polymorphic forms by using slurry with the compound of Formula I in 0.1M NaOH/methanol solution, followed by washing with MTBE, which was followed by air dry.

Form D of the compound of Compound I can have an XRPD spectrum as shown in FIG. 16, for example, with one or more, three or more, five or more, seven or more, ten or more, or all of the peaks shown in Table 2.

TABLE 2 XRPD Table of the polymorphic form, Form D of Compound I No. Pos. [°2Th.] Rel. Int. [%] 1 5.58 100 2 7.43 6.5 3 8.45 18.72 4 9.21 8.1 5 11.23 7.01 6 11.98 14.09 7 14.86 19.3 8 17.02 28.9 9 18.91 15.09 10 22.80 9.52 11 26.03 91.9 12 26.72 54.72

In another aspect, the present invention comprises another crystalline form (Form E) of the Formula I compound described above. Form E can exhibit an XRPD pattern with peaks at one or more of 5.6±0.3, 6.8±0.3, 8.6±0.3, 9.5±0.3, 11.8±0.3, 14.4±0.3, 17.1±0.3, 17.4±0.3, 18.0±0.3, 18.9±0.3, 20.0±0.3, 21.0±0.3, 22.3±0.3, 23.5±0.3, 25.5±0.3, 26.4±0.3, 28.3±0.3, 29.6±0.3, 30.7±0.3, 32.3±0.3, and 34.0±0.3 degrees 2-theta, such as the XRPD peaks described in Table 3. FIG. 17 shows an XRPD diffraction pattern of Form E.

TABLE 3 No. Pos. [°2Th.] Rel. Int. [%] 1 5.5698 65.4 2 6.8459 9.97 3 8.5515 23.62 4 9.5049 59.91 5 11.7857 11.04 6 14.3744 99 7 17.0602 17.22 8 17.4307 35.68 9 18.0062 34.51 10 18.8925 62.85 11 19.9711 74.64 12 21.0152 41.12 13 22.3471 26.86 14 22.8398 26.95 15 23.5282 100 16 25.496 34.92 17 26.3928 46.46 18 28.264 22.95 19 29.5631 16.22 20 30.7097 28.12 21 32.2629 25.41 22 34.0447 16.24 23 37.8132 7.49

To prepare a pharmaceutical composition containing the active substance, particularly an orally administered pharmaceutical composition, most preferably a tablet, procedures known in the art may be used. For example, tablets can be prepared according to the formulations and methods discussed in Remington: The Science and Practice of Pharmacy, which is hereby incorporated by reference for all purposes. Suitable tablets may be obtained, for example, by mixing the active substance(s) with known excipients, for example, inert diluents such as mannitol, sorbitol, xylitol, saccharose, calcium carbonate, calcium phosphate, or lactose, disintegrants such as croscarmellose sodium salt (cellulose carboxymethylether sodium salt, cross-linked), crospovidone, sodium starch glycolate, hydroxypropylcellulose (low-substituted), or maize starch, binders such as polyvinylpyrrolidone, copolymers of vinylpyrrolidone with other vinyl derivatives (copovidone), hydroxypropylcellulose, hydroxypropylmethylcellulose, microcrystalline cellulose, or starch, lubricants such as magnesium stearate, sodium stearyl fumarate, or talc and/or agents for obtaining delayed release, such as hydroxypropylmethylcellulose, carboxymethylcellulose, cellulose acetate phthalate, or polyvinyl acetate. The tablets may also comprise several layers. The following are some examples of pharmaceutical preparations which may be used according to the invention. They are intended purely as illustrations by way of example without restricting the subject matter of the invention thereto. All of the present crystalline polymorphs, i.e., Forms A, B, C, D, and E, can be used for pharmaceutical compositions as exemplified in the formulation examples below.

Formulation Example 1

Tablet 1 Ingredients mg Compound I 83.417 Mannitol 299.083 Microcrystalline cellulose 100.000 Croscarmellose sodium salt 10.000 Magnesium stearate 7.500 Total 500.000

Formulation Example 2

Tablet 2 Ingredients mg Compound I 83.417 Sorbitol 384.083 Povidone K25 25.000 Magnesium stearate 7.500 Total 500.000

Formulation Example 3

Tablet 3 Ingredients mg Compound I 41.708 Mannitol 149.542 Microcrystalline cellulose 50.000 Croscarmellose sodium salt 5.000 Magnesium stearate 3.750 Total 250.000

Formulation Example 4

By directly compressing the Compound I with the excipients sorbitol and magnesium stearate, tablets are obtained whose concentration of active substance corresponds to an amount of 80 mg, 40 mg, and 20 mg of free acid of Compound I.

Tablet Containing the Equivalent of 80 mg of Free Acid of Compound I.

Ingredient mg/tablet % Tablet Compound I 83.417 17.379 Sorbitol 389.383 81.121 Magnesium stearate 7.2 1.5 Total 480 100 Tablet Containing the Equivalent of 40 mg of Free Acid of Compound I.

Ingredient mg/tablet % Tablet Compound I 41.708 17.378 Sorbitol 194.692 81.122 Magnesium stearate 3.6 1.5 Total 240 100 Tablet Containing the Equivalent of 20 mg of Free Acid of Compound I.

Ingredient mg/tablet % Tablet Compound I 20.854 17.378 Sorbitol 97.346 81.122 Magnesium stearate 1.8 1.5 Total 120 100

Formulation Example 5

The Compound I is first mixed with mannitol, red iron oxide and hydroxypropylcellulose in an intensive mixer. Then magnesium stearate is added by sifting through a 0.8 mm screen and the mixture is subjected to dry granulation in a roller compactor. In parallel, hydrochlorothiazide is mixed with mannitol, microcrystalline cellulose, sodium glycol starch, and red iron oxide in an intensive mixer. Both this mixture and the granulated Compound I are sieved through a 0.8 mm screen, mixed together in a free fall blender, and finally subjected to a last mixing process with magnesium stearate screened through a 0.8 mm screen. A composition is obtained which can be compressed without any problems and the tablets produced from it exhibit good solubility for the active substances. This composition of active substances and excipients is compressed with a suitable tablet press. Tablets of the following composition are prepared, the amount of Compound I contained in each tablet corresponding to an amount of 80 mg of the free acid of Compound I.

Ingredient mg/tablet % Tablet Compound I 83.417 13.903 Hydrochlorothiazide 12.500 2.083 Mannitol 336.483 56.081 Cellulose microcrystalline 120.000 20.000 Sodium glycol starch 30.000 5.000 Red iron oxide 0.600 0.100 Hydroxypropylcellulose 5.000 0.833 Magnesium stearate 12.000 2.000 Total 600 100 The composition of the tablet may also be as follows:

Ingredient mg/tablet % Tablet %/Granules Compound I 83.417 13.903 83.417 Mannitol 10.983 1.831 10.983 Hydroxypropylcellulose 5.000 0.833 5.000 Red iron oxide 0.100 0.017 0.100 Magnesium stearate 0.500 0.083 0.500 Total 100.000 16.667 100.000 Hydrochlorothiazide 12.500 2.083 Mannitol 325.500 54.250 Cellulose microcrystalline 120.000 20.000 Sodium glycol starch 30.000 5.000 Red iron oxide 0.500 0.083 Magnesium stearate 11.500 1.917 Total 600.000 100.000

Formulation Example 6

Hydrochlorothiazide, Compound I, sorbitol, and red iron oxide are mixed in a free fall blender, passed through a 0.8 mm screen and, after the addition of magnesium stearate, processed in a free fall blender to form a powdered mixture. This composition of active substances and excipients is then compressed into tablets using a suitable tablet press. Tablets of the following composition are prepared, the amount of Compound I contained in each tablet corresponding to an amount of 80 mg of the free acid of Compound I.

Ingredient Mg/tablet % Tablet Compound I 83.417 13.903 Hydrochlorothiazide 12.500 2.083 Sorbitol 494.483 82.414 Red iron oxide 0.600 0.100 Magnesium stearate 9.000 1.500 Total 600.000 100.000

Formulation Example 7

Capsule Containing the Equivalent of 100 mg of Free Acid of Compound I.

Ingredients mg Compound I 100 Cellulose microcrystalline 170 Total 270

X-Ray Powder Diffraction (XRPD).

Approximately 2 mg of sample was gently compressed on the XRPD zero back ground single obliquely cut silica sample holder. The sample was then loaded into a D/MAX 2200 X-ray powder diffractometer (Rigaku) or a Philips X-Pert MPD diffractometer and analyzed using the following experimental conditions (Tube anode: Cu; Generator tension: 40 kV; Tube current: 40 mA; Wavelength alpha1: 1.54056 Å; Wavelength alpha2: 1.5444 Å; Start angle [2 theta]: 5; End angle [2 theta]: 50; and Continuous scan). For suspected novel forms a slightly slower scan speed was used over a range of 4-40° 2θ.

It is known in the art that for the same sample or test article measured by different X-ray powder diffractometers or, even by the same X-ray powder diffractometer but measured at different times or temperature or conditions, the values of peak positions at degree two-theta may have about ±0.3 or ±0.5 variations.

Raman Spectroscopy.

Samples were analyzed by a Nicolet Almega XR Dispersive Raman Microscope for its Raman spectrum using the following conditions (Exposure Time: 1.0 s; Acquisition No: 10; Pinhole Size: 25, 50 or 100 μm; Wavelength range: 2000˜300 cm⁻¹ (single grating); Laser: He—Ne 780 nm 100% power; Objective: 20×/0.40 or 50×/0.75 (magnifier/numerical aperture number)). Then the measured Raman spectra were corrected by baseline subtraction using the software OMNIC™ v7.3.

Simultaneous Thermal Analysis (STA).

Approximately 5 mg of sample was accurately weighed into a ceramic crucible and it was placed into the chamber of Perkin-Elmer STA 600 TGA/DTA analyzer at ambient temperature. The sample was then heated at a rate of 10° C./min from 25° C. to 300° C. during which time the change in weight was monitored as well as DTA signal. The purge gas used was nitrogen at a flow rate of 20 cm³/min.

Differential Scanning Calorimetry (DSC).

Approximately, 5 mg of each sample was weighed into an aluminum DSC pan and sealed non-hermetically with an aluminum lid. The sample was then loaded into a Perkin-Elmer Jade DSC and held at 25° C. Once a stable heat-flow response was obtained, the sample was then heated to 300° C. at a scan rate of 10° C./min and the resulting heat flow response was monitored. A 20 cm³/min helium purge was used. Prior to analysis, the instrument was temperature and heat flow verified using an indium standard.

Polarised Light Microscopy (PLM).

An Olympus BX50 microscope, equipped with an analyser and polariser, was used to observe each sample under polarised light. Micrographs of the sample were taken by using a JVC-TKC1380 digital camera connected to a PC running Studio QuickStart version 9.3.2. A 20×/0.5 (magnifier/numerical aperture (NA) value) objective was used to view samples and capture images.

Gravimetric Vapor Sorption (GVS).

Approximately 20 mg of sample was placed into a wire-mesh vapor sorption balance pan and loaded into an ‘IgaSorp’ vapor sorption balance (Hiden Analytical Instruments). The sample was then dried by maintaining a 0% humidity environment until no further weight change was recorded. Subsequently, the sample was then subjected to a ramping profile from 0-90% RH at 10% RH increments, maintaining the sample at each step until equilibration had been attained (99% step completion). Upon reaching equilibration, the % RH within the apparatus was ramped to the next step and the equilibration procedure repeated. After completion of the sorption cycle, the sample was then dried using the same procedure. The weight change during the sorption/desorption cycles were then monitored, allowing for the hygroscopic nature of the sample to be determined.

Biological Activities

Rat Pharmacokinetics.

Compound I was dosed to nonfasted male CD IGS rats (weighting 180-250 g, Charles River Laboratories) by single intravenous (IV, n=3/group) or oral gavage (PO, n=4/group, including control rat group for drug-free blood and brain collection) administration at a nominal dose levels of 3 mg/kg (IV) or 5 mg/kg (IV) and 10, 50, 100 mg/kg (PO) respectively. Compound was formulated in either DMSO/Solutol® HS 15/phosphate buffered saline, pH 7.4 (PBS) for both IV and PO dosing, or 10% (w/v) Povidone K12 in water for IV dosing or 10% (w/v) Povidone K25 in water for PO dosing, or 18% (w/v) CrosPovidone in water for PO dosing. An intravenous profile was obtained by taking serial or terminal blood samples at 3, 10, 30, 60, 120, 240, 360, 1440 min post dose. An oral profile was obtained by taking serial or terminal blood samples at 10, 30, 60, 120, 240, 360, 480, 1440 min post dose.

Plasma Sample Collection from Rats.

Animals were sedated under general inhalant anesthesia (3% isoflurane) for blood collection by cardiac puncture. Blood aliquots (300-400 μL) were collected in tubes coated with lithium heparin, mixed gently, then kept on ice and centrifuged at 2,500×g for 15 minutes at 4° C., within 1 hour of collection. For control animals, blood was collected by cardiac puncture. The plasma was then harvested and kept frozen at −20° C. until further processing. Plasma Sample Collection from Cannulated Rats. Blood collection was carried out from the jugular vein catheter. Blood aliquots (300-400 μL) were collected in tubes coated with lithium heparin, mixed gently, then kept on ice and centrifuged at 2,500×g for 15 minutes at 4° C., within 1 hour of collection. For control animals, blood was collected by cardiac puncture. The plasma was then harvested and kept frozen at −20° C. until further processing.

Brain Sample Collection from Rats.

Immediately after the blood sampling, rats were decapitated and the whole brains were quickly removed, rinsed with cold saline (0.9% NaCl, g/mL), surface vasculature ruptured, blotted with dry gauze, weighed and kept on ice until further processing within 1 hour of collection. Each brain was homogenized in 3 mL cold phosphate-buffered saline, pH 7.4 for 10 seconds on ice using Power Gen 125. The brain homogenate from each brain was then stored at −20° C. until further processing.

Plasma and brain samples were subjected to quantitative analysis by LC-MS/MS using compound-specific mass transitions. Drug concentration-time profiles were generated and non-compartmental PK analysis (using WinNonlin) used to generate estimates of half-life (T_(1/2)), clearance, volume of distribution (V_(ss)), and oral bioavailability (F %) (Gabriesson, J. and Weiner, D. Pharmacokinetic and Pharmacodynamic Data Analysis: Concepts and Applications. Swedish Pharmaceutical Press. 1997). The concentrations of the test compound in brain (ng/g brain tissue) and in plasma (ng/mL) as well as the ratio of the brain concentration and the plasma concentration at each time point were determined and reported.

For Compound I, the mean pharmacokinetic parameters are determined as following:

Dose F C_(max) T_(1/2) Clearance V_(ss) (mg/kg) Route (%) (ng/mL) (min) (mL/min/kg) (mL/kg) 3 IV 65 4 287 100 PO ~100 66008 124

Brain Plasma con- Con- Ratio Dose Dose Time centration centration Brain/Plasma (mg/kg) Route (mg/kg) (min) (ng/g brain) (ng/mL) (mL/g brain) 3 IV 5 30 153 11279 1.4% 3 IV 5 60 120 8161 1.8% 3 IV 5 180 23 1833 1.9% Compound Inhibition in a Live, Whole Cell Based Functional Assay:

There are several methods to measure whole length TrkA activation stimulated by its natural ligand or agonist NGF in live cells. For example, the PathHunter Profiling services offered by DiscoveRx (Fremont, Calif.). The PathHunter technology is an adaptation of enzyme fragment complementation that provides a novel, generic functional cell-based assay format for detecting protein-protein interactions. In this cell-based assay approach, with U2OS cell background, a small peptide epitope (PK) is expressed recombinantly on the intracellular C-terminus of TrkA (human full length). This is co-expressed with a larger sequence, termed enzyme acceptor (EA) that is attached to a cytoplasmic protein SHC1 which will interact with TrkA intracellularly. NGF induced activation of TrkA receptor causes either homo- or hetero-dimerization of TrkA resulting in cross-phosphorylation. The SHC1-EA fusion protein then binds the phosphorylated TrkA receptor forcing complementation of the PK and EA fragment. This interaction generates an active beta-galactosidase enzyme, which is detected using a chemiluminescent substrate. In such cell-based functional assays, Compound C of the present invention inhibits NGF stimulated TrkA activation at low nanomolar concentration (cellular IC₅₀ is about 50 nM, mean of triplicate), while virtually has no effect on either BDNF stimulated TrkB, or NT3 stimulated TrkC activation (IC₅₀ more than 10,000 nM in both cases, triplicate, with a positive control compound of pan-kinase inhibitor, staurosporine or K-252a, an internal agonist control and a negative control compound).

Cell Viability and Proliferation Assays.

To assess the chemosensitivity of tumor cells, cell viability is measured by CellTiter-Glo® Luminescent Cell Viability Assay (Promega; Wis., USA) per the manufacturer's instruction. Briefly, 5×103 to 7×105 cells/ml are cultured in sterile 96-well plates in the presence of increasing concentrations of the drugs (test article, 0 to 100 μM), or vehicle in RPMI medium. The plates are then incubated for 24 to 96 h, and then 100 μl of CellTiter-Glo reagent is added to lyse the cells. After a 10-min incubation at room temperature, the luminescence is recorded in a luminometer with an integration time of 1 s per well. The luminescence signals for the drug-treated cells are normalized by the luminescence signal obtained from vehicle-treated cells. As an alternative method to quantitate cell viability, the trypan blue exclusion dye method was used. Vehicle- or drug-treated cells were assayed by adding trypan blue solution (0.4% in phosphate-buffered saline [PBS]) to the culture medium. After 3 min, the number of dead cells that retained the dye is compared to the total number of cells to calculate cell viability. GraphPad Prism 5 software is used to calculate IC50 and plot effect-dose curve of drugs. Multiplate reader: EnVision 2104 (PerkinElmer). % of control variability=100*[(X(drug_treated)−L(baseline))/(H(vehicle_control)−L(baseline))]. Such assays show that for example, Compound I, has IC50 value about 2 to 5 μM in human pancreatic cancer cells (from ATCC) of AsPC-1, MIA PaCa-2, BxPC-3, Capan-1 and Panc-1; about 2 to 8 μM in human liver cancer cells of SK-HEP-1 and HepG2; and about 7 μM in human stomach cancer cells of NCI-N87, after 24 h or 48 h or 96 h incubation. Taxol, erlotinib, sorafenib and gemcitabine are used as controls, and the compounds of present inventions are synergistic or additive with gemcitabine, taxol, erlotinib or sorafenib in pancreatic or liver cancer cells.

Rat CFA-induced Inflammatory Pain Model.

Hyperalgesia was induced by subcutaneously injecting 50 μL of CFA (Sigma-Aldrich, St. Louis, Mo., USA) into the plantar surface of the left hind paw of the rats using a 30-gauge hypodermic needle under sevoflurane anesthesia. The classical signs of inflammation, including edema and redness, for up the last day of tests were recorded. To assess the effect of test article on CFA-induced inflammatory pain, the rats were anesthetized with sevoflurane 3 hours after CFA injection and then injected 50 μL of either 1 mM test article (n=6) or Saline (n=4) subcutaneously (S.C.) into the same site as the CFA injection, using a 30-gauge hypodermic needle under sevoflurane anesthesia, according to published method (Ueda K., et al, J Pharmacol. Sci., 2010; 112(4):438-43). Paw withdrawal latencies (thermal hyperalgesia) are measured before and at 2 and 4 and 2, 4, and 7 days after CFA injection. Mechanical thresholds were also measured in the same way with either Formula 1 compound (n=6) or Saline (n=4) at similar different time points (for example, 1, 3 hour and 3 days). The noxious heat and mechanical thresholds were separately measured in each group of rats. The threshold was measured 3-5 times in each rat and then averaged. Stimulus interval was 5 min. The analgesic effect of Compound I on this rat CFA-induced inflammatory pain model is given in FIG. 1, where it clearly shown that Compound I is efficacious in relieving the pain in this rat pain model.

Chronic Constriction Injury (CCI) Model of Neuropathic Pain in Rat.

The CCI model is one of the most commonly used mono-neuropathic pain model firstly described in details by Bennett and Xie (Bennett G J, Xie Y K. Pain. 1988; 33(1):87-107). It mimics important clinical chronic pain symptoms such as mechanical allodynia and thermal hyperalgesia. Chronic constriction injury of the sciatic nerve was produced by tying four loose ligatures around the left sciatic nerve according to the method of Bennett and Xie. This procedure resulted in tactile allodynia in the left hindpaw. Calibrated von Frey filaments were used to determine the lowest mechanical (tactile) threshold required to evoke a brisk paw withdrawal reflex in the rat hindpaws. Rats were allowed to acclimatize in wire mesh cages for 15-20 min prior to von Frey testing. Assessment of paw withdrawal thresholds (PWTs) using von Frey filaments was undertaken prior to CCI-surgery (pre-surgery baseline on day 0). Before the drug dosing on day 14, the pre-dose baseline was recorded for each rat. Rats were included in the study only if they did not exhibit motor dysfunction (e.g., paw dragging or dropping) and their PWT was below to 4 g. Drug-naïve CCI-rats (n=4-6 per group) were used. The oral (PO) gavage vehicle was either 10% (w/v) Povidone K25 in water for PO dosing, or 18% (w/v) CrosPovidone in water for PO dosing, or 0.5% CMC-Na/0.1% Tween 80 in distilled water for PO dosing. The positive control gabapentin was dissolved in the vehicle and orally given at 100 mg/kg (by oral gavage). Test article was dissolved or suspended in the vehicle and orally given at 25, 50, 100 and 150 mg/kg. Each CCI-rat was administered a single oral dose of test article, gabapentin or vehicle control, 2 hours before assessment of PWT.

The results have demonstrated, as shown in FIG. 2, that oral administration of Compound I of present invention significantly reduced mechanical allodynia in CCI rats of neuropathic pain model in a dose-dependent manner. In addition, at the same oral dose of 100 mg/kg, Compound I is about 100% more effective in suppressing mechanical allodynia in CCI neuropathic pain compared to gabapentin, the current gold standard medication for neuropathic pain. Of note, CCI-rats dosed with gabapentin have shown drowsiness or motor incoordination, which is consistent with known side effect of gabapentin. However, no such effect or other abnormality was observed in CCI-rats dosed with Compound I.

Spinal Nerve Ligation (SNL) Mono-Neuropathic Pain Model in Rat.

The surgical procedure will be performed according to the method firstly described by Kim and Chung (Kim S H, Chung J M. Pain. 1992; 50(3):355-63.). This procedure will result in tactile allodynia in the left hindpaw. Rats will be included in the study only if they do not exhibit motor dysfunction (e.g., paw dragging or dropping) and their PWT is below to 4.0 g. The dose-response anti-allodynia effects of test compound: on day 14 after surgery, rats were treated with test article at one of four doses, vehicle or positive control by oral gavage, and PWT was determined by calibrated von Frey filaments at time points of 0 (right before the drug dosing, Pre-Dose Baseline), 0.5, 1, 2, 4 and 6 hr. The anti-allodynia effects of repeated administration of test article: Administration of test article was started on day 7 after surgery, once a day for 7 days. PWT was determined by calibrated von Frey filaments, 2 hour after test article dosing each day. After 7 days dosing, the measurement were continued, every other day without compound dosing for another 7 days. PWT was determined at the time points as given above. The results have demonstrated that oral administration of Compound I of present invention significantly reduced mechanical allodynia in SNL rats of neuropathic pain model in a dose-dependent manner.

Streptozotocin-Induced Diabetic Poly-Neuropathic Pain Model in Rat.

Diabetic peripheral neuropathy is a long-term complication of diabetes mellitus. Rats were received i.p. injections of streptozotocin (STZ, 50 mg/kg dissolved in citrate buffer at pH 4.5 immediately before the injection) to induce insulin-dependent diabetes mellitus and produce tactile allodynia. One week later, blood glucose level was assayed, from samples taken from the tail vein, using standard test strips and colorimeter. Only animals with a blood glucose level >350 mg/dL were considered diabetic and included for the testing. Typical features of neuropathic pain (tactile allodynia) were developed in hindpaws beginning around 2 to 3 weeks after STZ injection. After 4 weeks, a stable level of allodynia was reached. At this point, the rats with PWT below 4.5 g were enrolled for compound testing. The allodynic state was remain intact until the 8^(th) week after STZ injection. All animals were observed daily and weighed regularly during the study period. This model of neuropathic pain mimics the symptoms of neuropathy in diabetic patients (Lynch J J, 3rd, et al Eur J Pharmacol. 1999; 364(2-3):141-6; Calcutt N A, J Neurol Sci. 2004; 220(1-2):137-9). The dose-response anti-allodynia effects of test compound: On day 28 after STZ injection, rats were treated with test compound at one of four doses, or controls (vehicle and positive) by oral gavage, and PWT was determined by calibrated von Frey filaments at time points of 0 (right before the drug dosing, Pre-Dose Baseline), 0.5, 1, 2, 4 and 6 hr. Tolerance effects: 6 days following the day 28 test, i.e. on day 34 after STZ injection, the same procedure on day 28 was repeated on day 34 with the same group of STZ-rats treated with the same (effective) dose as on day 28. The two results of anti-allodynia effects of test compound as measured on day 28 and on day 34 were compared to see if there was any tolerance effect of test compound in animals. The anti-allodynia effects of repeated administration of test compound: Administration (p.o.) of test compound was started on day 21 after STZ injection, once a day for 7 days. PWT was determined by calibrated von Frey filaments once a day, 1 hour after compound dosing. After 7 days dosing, the measurement was continued, every other day without compound dosing for another 7 days. PWT was determined at the time points as given above.

Pharmaceutical Compositions of the Invention

In one aspect, the present invention provides pharmaceutical compositions comprising one or more compounds of the present invention including the compound having structural Compound I.

The present pharmaceutical compositions contain a therapeutically effective amount of the present invention, preferably in purified form, together with a suitable amount of a pharmaceutically acceptable vehicle, so as to provide a form for proper administration to a patient. When administered to a patient, the present compounds and the pharmaceutically acceptable vehicles are preferably sterile. Water is a preferred vehicle when a compound is administered intravenously. Saline solutions and aqueous dextrose and glycerol solutions can also be employed as liquid vehicles, particularly for injectable solutions. Suitable pharmaceutical vehicles also include excipients such as starch, glucose, lactose, sucrose, gelatin, malt, rice, flour, chalk, silica gel, sodium stearate, glycerol monostearate, talc, sodium chloride, dried skim milk, glycerol, propylene, glycol, water, ethanol and the like. The present pharmaceutical compositions, if desired, can also contain minor amounts of wetting or emulsifying agents, or pH buffering agents. In addition, auxiliary, stabilizing, thickening, lubricating and coloring agents may be used.

Pharmaceutical compositions may be manufactured by means of conventional mixing, dissolving, granulating, dragee-making, levigating, emulsifying, encapsulating, entrapping or lyophilizing processes. Pharmaceutical compositions may be formulated in conventional manner using one or more physiologically acceptable carriers, diluents, excipients or auxiliaries, which facilitate processing of compounds of the invention into preparations that can be used pharmaceutically. Proper formulation is dependent upon the route of administration chosen.

The present pharmaceutical compositions can take the form of solutions, suspensions, emulsion, tablets, pills, pellets, capsules, capsules containing liquids, powders, sustained-release formulations, suppositories, emulsions, aerosols, sprays, suspensions, or any other form suitable for use. In some embodiments, the pharmaceutically acceptable vehicle is a capsule (see e.g., Grosswald et al., U.S. Pat. No. 5,698,155). Other examples of suitable pharmaceutical vehicles have been described in the art (see Remington: The Science and Practice of Pharmacy, Philadelphia College of Pharmacy and Science, 20^(th) Edition, 2000).

For topical administration the compound may be formulated as solutions, gels, ointments, creams, suspensions, etc. as is well-known in the art.

Systemic formulations include those designed for administration by injection, e.g., subcutaneous, intravenous, intramuscular, intrathecal or intraperitoneal injection, as well as those designed for transdermal, transmucosal, oral or pulmonary administration. Systemic formulations may be made in combination with a further active agent.

In some embodiments, the present compounds, are formulated in accordance with routine procedures as a pharmaceutical composition adapted for intravenous administration to human beings. Typically, compounds for intravenous administration are solutions in sterile isotonic aqueous buffer. For injection, the present compounds, or salts, solvates, esters, and/or prodrugs thereof, may be formulated in aqueous solutions, preferably, in physiologically compatible buffers such as Hanks' solution, Ringer's solution, or physiological saline buffer. The solution may contain formulatory agents such as suspending, stabilizing and/or dispersing agents. When necessary, the pharmaceutical compositions may also include a solubilizing agent. Pharmaceutical compositions for intravenous administration may optionally include a local anesthetic such as lignocaine to ease pain at the site of the injection. Generally, the ingredients are supplied either separately or mixed together in unit dosage form, for example, as a lyophilized powder or water free concentrate in a hermetically sealed container such as an ampoule or sachette indicating the quantity of active agent. When the present compounds, are administered by infusion, it can be dispensed, for example, with an infusion bottle containing sterile pharmaceutical grade water or saline. When the present compounds are administered by injection, an ampoule of sterile water for injection or saline can be provided so that the ingredients may be mixed prior to administration.

For transmucosal administration, penetrants appropriate to the barrier to be permeated are used in the formulation. Such penetrants are generally known in the art.

Pharmaceutical compositions for oral delivery may be in the form of tablets, lozenges, aqueous or oily suspensions, granules, powders, emulsions, capsules, syrups, or elixirs, for example. Orally administered pharmaceutical compositions may contain one or more optional agents, for example, sweetening agents such as fructose, aspartame or saccharin; flavoring agents such as peppermint, oil of wintergreen, or cherry coloring agents and preserving agents, to provide a pharmaceutically palatable preparation. Moreover, in tablet or pill form, the compositions may be coated to delay disintegration and absorption in the gastrointestinal tract, thereby providing a sustained action over an extended period of time. Selectively permeable membranes surrounding an osmotically active driving compound are also suitable for orally administered compounds of the invention. In these later platforms, fluid from the environment surrounding the capsule is imbibed by the driving compound, which swells to displace the agent or agent composition through an aperture. These delivery platforms can provide an essentially zero order delivery profile as opposed to the spiked profiles of immediate release formulations. A time delay material such as glycerol monostearate or glycerol stearate may also be used. Oral compositions can include standard vehicles such as mannitol, lactose, starch, magnesium stearate, sodium saccharine, cellulose, magnesium carbonate, etc. Such vehicles are preferably of pharmaceutical grade.

For oral liquid preparations such as, for example, suspensions, elixirs and solutions, suitable carriers, excipients or diluents include water, saline, alkyleneglycols (e.g., propylene glycol), polyalkylene glycols (e.g., polyethylene glycol) oils, alcohols, slightly acidic buffers between pH 4 and pH 6 (e.g., acetate, citrate, ascorbate at between about 5.0 mM to about 50.0 mM) etc. Additionally, flavoring agents, preservatives, coloring agents, bile salts, acylcarnitines and the like may be added.

For buccal administration, the pharmaceutical compositions may take the form of tablets, lozenges, etc. formulated in conventional manner.

Liquid drug formulations suitable for use with nebulizers and liquid spray devices and EHD aerosol devices will typically include a compound of the invention with a pharmaceutically acceptable vehicle. In some embodiments, the pharmaceutically acceptable vehicle is a liquid such as alcohol, water, polyethylene glycol or a perfluorocarbon. Optionally, another material may be added to alter the aerosol properties of the solution or suspension of compounds disclosed herein. Preferably, this material is liquid such as an alcohol, glycol, polyglycol or a fatty acid. Other methods of formulating liquid drug solutions or suspension suitable for use in aerosol devices are known to those of skill in the art (see, e.g., Biesalski, U.S. Pat. No. 5,112,598; Biesalski, U.S. Pat. No. 5,556,611).

The present compounds may also be formulated in rectal or vaginal pharmaceutical compositions such as suppositories or retention enemas, e.g., containing conventional suppository bases such as cocoa butter or other glycerides.

In addition to the formulations described previously, the present compounds may also be formulated as a depot preparation. Such long acting formulations may be administered by implantation (for example, subcutaneously or intramuscularly) or by intramuscular injection. Thus, for example, the present compounds may be formulated with suitable polymeric or hydrophobic materials (for example, as an emulsion in an acceptable oil) or ion exchange resins, or as sparingly soluble derivatives, for example, as a sparingly soluble salt.

Therapeutic Doses

The present compound(s), their crystalline form(s) and a pharmaceutically acceptable vehicle is provided, will generally be used in an amount effective to treat or prevent diseases or disorders including: cancer, anxiety, generalized pain disorder, acute pain, chronic pain, inflammatory pain, and neuropathic pain.

The amount of the present compounds that will be effective in the treatment of a particular disorder or condition disclosed herein will depend on the nature of the disorder or condition, and can be determined by standard clinical techniques known in the art. In addition, in vitro or in vivo assays may optionally be employed to help identify optimal dosage ranges. The amount of the present compounds administered will, of course, be dependent on, among other factors, the subject being treated, the weight of the subject, the severity of the affliction, the manner of administration and the judgment of the prescribing physician.

For example, the dosage may be delivered in a pharmaceutical composition by a single administration, by multiple applications or controlled release. In some embodiment, the present compounds are delivered by oral sustained release administration. Dosing may be repeated intermittently, may be provided alone or in combination with other drugs and may continue as long as required for effective treatment of the disease state or disorder.

Suitable dosage ranges for oral administration to a patient in need depend on the potency of the present compounds, but are generally between about 0.1 mg to about 800 mg of a compound of the invention per kilogram body weight; more preferably, between about 0.01 mg to about 50 mg of a compound of the invention per kilogram body weight; still more preferably, between about 0.05 mg to about 20 mg of a compound of the invention per kilogram body weight; and the patient is an animal; more preferably, a mammal; and most preferably, a human. Dosage ranges may be readily determined by methods known to the artisan of ordinary skill.

Suitable dosage ranges for intravenous (i.v.) administration to a patient in need are about 0.1 mg to about 200 mg per kilogram body weight; more preferably, between about 0.01 mg to about 20 mg of a compound of the invention per kilogram body weight; and the patient is an animal; more preferably, a mammal; and most preferably, a human.

Suitable dosage ranges for intranasal administration to a patient in need are generally about 0.1 mg/kg body weight to about 10 mg/kg body weight; more preferably, between about 0.01 mg to about 1 mg of a compound of the invention per kilogram body weight; and the patient is an animal; more preferably, a mammal; and most preferably, a human.

Suppositories generally contain about 0.1 milligram to about 150 milligrams of a compound of the invention per kilogram body weight and comprise active ingredient in the range of about 0.5% to about 10% by weight.

Recommended dosages for intradermal, intramuscular, intraperitoneal, subcutaneous, epidural, sublingual or intracerebral administration are in the range of about 0.1 mg to about 800 mg per kilogram of body weight; and the patient is an animal; more preferably, a mammal; and most preferably, a human.

Effective doses may be extrapolated from dose-response curves derived from in vitro or animal model test systems. Such animal models and systems are well-known in the art.

The present compounds are preferably assayed in vitro and in vivo, for the desired therapeutic or prophylactic activity, prior to use in humans. For example, in vitro assays can be used to determine whether administration of a specific compound of the invention or a combination of compounds is preferred for reducing the pain or killing the cancer cells. The present compounds may also be demonstrated to be effective and safe using animal model systems.

Preferably, a therapeutically effective dose of the present compounds will provide therapeutic benefit without causing substantial toxicity. Toxicity of the present compounds may be determined using standard pharmaceutical procedures and may be readily ascertained by the skilled artisan. The dose ratio between toxic and therapeutic effect is the therapeutic index. The present compounds generally exhibit particularly high therapeutic indices in treating associated disease and disorders or conditions. The dosage of the present compounds will preferably be within a range of circulating concentrations that include an effective dose with little or no toxicity.

Combination Therapy

In certain embodiments of the present invention, the present compounds can be used in combination therapy with at least one additional active or therapeutic agent. The present compounds and the at least one additional active or therapeutic agent can act additively or, more preferably, synergistically. In some embodiments, the present compounds are administered concurrently, sequentially, or separately with the administration of another therapeutic agent. Exemplary active agents include, but are not limited to, aceglatone, aclarubicin, altretamine, aminoglutethimide; 5-aminogleavulinic acid, amsacrine, anastrozole, ancitabine hydrochloride, 17-1a antibody, antilymphocyte immunoglobulins, antineoplaston a10, asparaginase, pegaspargase, azacitidine, azathioprine, batimastat, benzoporphyrin derivative, bicalutamide, bisantrene hydrochloride, bleomycin sulphate, brequinar sodium, broxuridine, busulphan, campath-ih, caracemide, carbetimer, carboplatin, carboquone, carmofur, carmustine, chlorambucil, chlorozotocin, chromomycin, cisplatin, cladribine, corynebacterium parvum, cyclophosphamide, cyclosporin, cytarabine, dacarbazine, dactinomycin, daunorubicin hydrochloride, decitabine, diaziquone, dichlorodiethylsulphide, didemnin b., docetaxel, doxifluridine, doxorubicin hychloride, droloxifene, echinomycin, edatrexate, elliptinium, elmustine, enloplatin, enocitabine, epirubicin hydrochloride, estramustine sodium phosphate, etanidazole, ethoglucid, etoposide, fadrozole hydrochloride, fazarabine, fenretinide, floxuridine, fludarabine phosphate, fluorouracil, flutamide, formestane, fotemustine, gallium nitrate, gencitabine, gusperimus, homoharringtonine, hydroxyurea, idarubicin hydrochloride, ifosfamide, ilmofosine, improsulfan tosylate, inolimomab, interleukin-2; irinotecan, jm-216, letrozole, lithium gamolenate, lobaplatin, lomustine, lonidamine, mafosfamide, meiphalan, menogaril, mercaptopurine, methotrexate, methotrexate sodium, miboplatin, miltefosine, misonidazole, mitobronitol, mitoguazone dihydrochioride, mitolactol, mitomycin, mitotane, mitozanetrone hydrochloride, mizoribine, mopidamol, muitlaichilpeptide, muromonab-cd3, mustine hydrochloride, mycophenolic acid, mycophenolate mofetil, nedaplatin, nilutamide, nimustine hydrochloride, oxaliplatin, paclitaxel, pcnu, penostatin, peplomycin sulphate, pipobroman, pirarubicin, piritrexim isethionate, piroxantrone hydrochloride, plicamycin, porfimer sodium, prednimustine, procarbazine hydrochloride, raltitrexed, ranimustine, razoxane, rogletimide, roquinimex, sebriplatin, semustine, sirolimus, sizofiran, sobuzoxane, sodium bromebrate, sparfosic acid, sparfosate sodium, sreptozocin, sulofenur, tacrolimus, tamoxifen, tegafur, teloxantrone hydrochloride, temozolomide, teniposide, testolactone, tetrasodium mesotetraphenylporphine-sulphonate, thioguanine, thioinosine, thiotepa, topotecan, toremifene, treosulfan, trimetrexate, trofosfamide, tumor necrosis factor, ubenimex, uramustine, vinblastine sulphate, vincristine sulphate, vindesine sulphate, vinorelbine tartrate, vorozole, zinostatin, zolimomab aritox, zorubicin hydrochloride, an inhibitor of protein kinase A (PKA) or PKC, an inhibitor of cAMP signaling, a nonsteroidal anti-inflammatory drug, a prostaglandin synthesis inhibitor, a local anesthetic, an anticonvulsant, an antidepressant, an opioid receptor agonist, and a neuroleptic, a benzodiazepine, a barbiturate, a neurosteroid and a inhalation anesthetic, a anesthetic and another pain killer and the like, either individually or in any combination.

All publications and patent applications herein are incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference. The foregoing detailed description has been given for clearness of understanding only and no unnecessary limitations should be understood therefrom as modifications will be obvious to those skilled in the art. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed inventions, or that any publication specifically or implicitly referenced is prior art.

Embodiments of this invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those of ordinary skill in the art upon reading the foregoing description. The inventors expect skilled artisans to employ such variations as appropriate, and the inventors intend for the invention to be practiced otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is encompassed by the invention unless otherwise indicated herein or otherwise clearly contradicted by context. 

What is claimed is:
 1. A method of treating pain in a patient, comprising: administering to a patient in need of said treating, a crystalline polymorph Form A of Compound I, sodium 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoate, with the following structure:

characterized by having x-ray powder diffraction pattern peak positions at degree two-theta of 10.0±0.3, 20.1±0.3, and 23.6±0.3.
 2. The method of claim 1, wherein the administered crystalline polymorph is further characterized by having x-ray powder diffraction pattern peak positions at degree two-theta of 14.5±0.3 and 18.1±0.3.
 3. The method of claim 1, wherein the administered crystalline polymorph is further characterized by having x-ray powder diffraction pattern peak positions at degree two-theta of 9.7±0.3 and 21.2±0.3.
 4. The method of claim 1, wherein the administered crystalline polymorph is further characterized by having x-ray powder diffraction pattern peak positions at degree two-theta of 14.5±0.3, 18.1±0.3, 9.7±0.3, and 21.2±0.3.
 5. The method of claim 1, wherein the administered crystalline polymorph exhibits an x-ray powder diffraction pattern that is substantially similar to that of FIG.
 4. 6. The method of claim 1, wherein the administered crystalline polymorph exhibits a Raman spectrum that is substantially similar to that of FIG.
 5. 7. The method of claim 1, wherein the administered crystalline polymorph exhibits a differential scanning calorimetry thermogram having an endotherm with an onset of about 244° C.
 8. The method of claim 1, wherein the administered crystalline polymorph exhibits a differential scanning calorimetry thermogram having an endotherm with a peak of about 250° C.
 9. The method of claim 1, wherein said pain is neuropathic pain.
 10. A method of treating pain in a patient, comprising: administering to a patient in need of said treating, a crystalline polymorph Form A of Compound I, sodium 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoate, with the following structure:

characterized by having an x-ray powder diffraction pattern exhibiting three or more peak positions at degree two-theta selected from the group consisting of: 7.160, 8.757, 9.820, 10.161, 12.459, 14.641, 15.219, 17.680, 18.240, 19.104, 20.220, 21.381, 22.579, 23.721, 24.898, 25.761, 25.522, 27.161, 28.321, 29.481, 30.921, and 34.281.
 11. The method of claim 10, wherein the administered crystalline polymorph exhibits an x-ray powder diffraction pattern having five or more peak positions at degree two-theta selected from the group consisting of: 7.160, 8.757, 9.820, 10.161, 12.459, 14.641, 15.219, 17.680, 18.240, 19.104, 20.220, 21.381, 22.579, 23.721, 24.898, 25.761, 25.522, 27.161, 28.321, 29.481, 30.921, and 34.281.
 12. The method of claim 10, wherein the administered crystalline polymorph exhibits an x-ray powder diffraction pattern having seven or more peak positions at degree two-theta selected from the group consisting of: 7.160, 8.757, 9.820, 10.161, 12.459, 14.641, 15.219, 17.680, 18.240, 19.104, 20.220, 21.381, 22.579, 23.721, 24.898, 25.761, 25.522, 27.161, 28.321, 29.481, 30.921, and 34.281.
 13. The method of claim 10, wherein the administered crystalline polymorph exhibits an x-ray powder diffraction pattern having ten or more peak positions at degree two-theta selected from the group consisting of: 7.160, 8.757, 9.820, 10.161, 12.459, 14.641, 15.219, 17.680, 18.240, 19.104, 20.220, 21.381, 22.579, 23.721, 24.898, 25.761, 25.522, 27.161, 28.321, 29.481, 30.921, and 34.281.
 14. The method of claim 10, wherein the administered crystalline polymorph exhibits an x-ray powder diffraction pattern having peak positions at degree two-theta of: 7.160, 8.757, 9.820, 10.161, 12.459, 14.641, 15.219, 17.680, 18.240, 19.104, 20.220, 21.381, 22.579, 23.721, 24.898, 25.761, 25.522, 27.161, 28.321, 29.481, 30.921, and 34.281.
 15. The method of claim 10, wherein said pain is neuropathic pain.
 16. A method of treating pain in a patient, comprising administering to a patient in need of said treating a composition, comprising: a) a crystalline polymorph Form A of Compound I, sodium 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoate, with the following structure:

characterized by having x-ray powder diffraction pattern peak positions at degree two-theta of 10.0±0.3, 20.1±0.3, and 23.6±0.3; or b) a combination of said crystalline polymorph Form A of Compound I and an amorphous form of Compound I; and one or more pharmaceutically acceptable excipients.
 17. The method of claim 16, wherein said pain is neuropathic pain.
 18. A method of treating pain in a patient, comprising administering to a patient in need of said treating a solid or semi-solid dosage form, comprising: a) a crystalline polymorph Form A of Compound I, sodium 4-((3-(4-cyclohexylpiperazin-1-yl)-6-oxo-6H-anthra[1,9-cd]isoxazol-5-yl)amino)benzoate, with the following structure:

characterized by having x-ray powder diffraction pattern peak positions at degree two-theta of 10.0±0.3, 20.1±0.3, and 23.6±0.3; or b) a combination of said crystalline polymorph Form A of Compound I and an amorphous form of Compound I.
 19. The method of claim 18, wherein the administered solid or semi-solid dosage form comprises one or more of a tablet, hard capsule, soft capsule, powder, suppository, and gel.
 20. The method of claim 18, wherein the administered solid or semi-solid dosage form comprises one or more of an injectable form, a transdermal patch, a sprayable form, and an implantable depot.
 21. The method of claim 18, wherein said pain is neuropathic pain.
 22. The method of claim 1, wherein said pain is inflammatory pain.
 23. The method of claim 10, wherein said pain is inflammatory pain.
 24. The method of claim 16, wherein said pain is inflammatory pain.
 25. The method of claim 18, wherein said pain is inflammatory pain.
 26. The method of claim 1, wherein said patient is a human.
 27. The method of claim 16, wherein said patient is a human.
 28. The method of claim 18, wherein said patient is a human.
 29. The method of claim 16, wherein the combination is formulated for oral, transdermal, or transmucosal administration.
 30. The method of claim 29, wherein the combination, for oral administration is in the form of a tablet, a lozenge, an aqueous suspension, an oily suspension, a capsule, granules, a powder, an emulsion, a syrup, or an elixir.
 31. The method of claim 16, further comprising administering an opioid receptor agonist. 